Method of fabricating bump structure and bump structure

Patent metadata

Field	Value
Publication number	US-9257401-B2
Application number	US-201514662295-A
Country	US
Kind code	B2
Filing date	Mar 19, 2015
Priority date	May 12, 2010
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A method of forming a semiconductor device includes forming an under-bump metallurgy (UBM) layer overlying a portion of a metal pad region within an opening of an encapsulating layer over a semiconductor substrate, and forming a bump layer overlying the UBM layer to fill the opening of the encapsulating layer. A removal process is initiated on an upper surface of the encapsulating layer and a coplanar top surface of the bump layer to remove the upper surface of the encapsulating layer until a top portion of the bump layer protrudes from the encapsulating layer.

First claim

What is claimed is:

1. A method of forming a semiconductor device, the method comprising:
forming an under-bump metallurgy (UBM) layer overlying a portion of a metal pad region within an opening of an encapsulating layer over a semiconductor substrate;
forming a bump layer overlying the UBM layer to fill the opening of the encapsulating layer; and
initiating a removal process on an upper surface of the encapsulating layer and a coplanar top surface of the bump layer to remove the upper surface of the encapsulating layer until a top portion of the bump layer protrudes from the encapsulating layer.

2. The method of claim 1 , wherein forming the UBM layer comprises forming the UBM layer within the encapsulating layer comprising an underfill material or a dielectric material.

3. The method of claim 1 , wherein forming the bump layer comprises forming a solder layer.

4. The method of claim 1 , wherein forming the bump layer comprises forming a copper layer to a thickness greater than 40 μm.

5. The method of claim 1 , wherein forming the UBM layer comprises forming at least one of a titanium layer or a copper layer.

6. The method of claim 1 , wherein the removal process reduces a thickness of the encapsulating layer to form a ratio of a thickness of the top portion of the bump layer to a thickness of the bump layer in a range from 0 to 0.98.

7. The method of claim 1 , wherein initiating the removal process comprises initiating a removal process comprising a buffing process.

8. The method of claim 1 , wherein initiating the removal process comprises initiating the removal process on the upper surface of the encapsulating layer, the coplanar top surface of the bump layer, and a coplanar top surface of the UBM layer.

9. The method of claim 1 , further comprising, prior to initiating the removal process, removing conductive material from the bump layer so that the top surface of the bump layer is coplanar with the upper surface of the encapsulating layer.

10. The method of claim 9 , wherein removing conductive material from the bump layer comprises performing an etch process.

11. The method of claim 9 , wherein removing conductive material from the bump layer comprises performing a planarization process.

12. The method of claim 9 , wherein removing conductive material from the bump layer comprises removing a portion of the UBM layer.

13. A method of forming a semiconductor device, the method comprising:
forming an under-bump metallurgy (UBM) layer overlying a portion of a metal pad region within an opening of an encapsulating layer over a semiconductor substrate;
filling the opening of the encapsulating layer with a bump layer and a cap layer, the bump layer and the cap layer overlying the UBM layer; and
initiating a removal process on an upper surface of the encapsulating layer and a coplanar top surface of the bump layer to remove the upper surface of the encapsulating layer until a top portion of the bump layer protrudes from the encapsulating layer.

14. The method of claim 13 , wherein filling the opening of the encapsulating layer with a cap layer comprises forming at least one of a copper layer, a nickel layer, or a gold layer.

15. The method of claim 13 , wherein filling the opening of the encapsulating layer comprises forming the cap layer between the bump layer and the UBM layer.

16. The method of claim 13 , wherein filling the opening of the encapsulating layer comprises forming a bottom portion of the bump layer between the cap layer and the UBM layer.

17. The method of claim 13 , wherein initiating the removal process comprises initiating the removal process on the upper surface of the encapsulating layer, the coplanar top surface of the bump layer, and a coplanar top surface of the UBM layer.

18. The method of claim 13 , further comprising, prior to initiating the removal process, removing conductive material from the bump layer so that the top surface of the bump layer is coplanar with the upper surface of the encapsulating layer.

19. A semiconductor device, comprising:
a semiconductor substrate comprising a metal pad region;
an encapsulating layer overlying the semiconductor substrate having an opening over a portion of the metal pad region;
a bump layer in the opening and electrically connected to the portion of the metal pad region, wherein a top portion of the bump layer protrudes from an upper surface of the encapsulating layer; and
an under-bump metallurgy (UBM) layer in the opening and electrically connected to the portion of the metal pad region, wherein the UBM layer is between the bump layer and the portion of the metal pad region, and a top surface of the UBM layer is level with a top surface of the bump layer.

20. The semiconductor device of claim 19 , wherein the bump layer comprises a cap layer.

Assignees

• Taiwan Semiconductor Mfg

Inventors

• Hsu Chun-Lei
• Ho Ming-Che
• Cheng Ming-Da
• Liu Chung-Shi

Classifications

• H10W72/9415

  relative to the surface, e.g. recessed, protruding · CPC title

• H10W72/01955

  by using masks · CPC title

• H10W72/01935

  by plating, e.g. electroless plating or electroplating · CPC title

• H10W72/01933

  in liquid form, e.g. spin coating, spray coating or immersion coating · CPC title

• H10W72/01255

  by using masks · CPC title